The Great Blue Hole

ocean · geology · Belize · cave

Perfectly circular crater. The Great Blue Hole is shaped like a giant circle and measures 318 meters across, that's longer than three football fields! It's 124 meters deep, making it one of the deepest underwater sinkholes in the world.

Ancient cave collapse. This hole wasn't always underwater. It started as a limestone cave system that formed during ice ages when ocean levels were much lower than today.

Flooded by rising seas. When glaciers melted and sea levels rose again, water filled up the cave from the bottom, creating the stunning blue hole we see today.

Super old formation. Scientists studied stalactites found inside the hole and discovered it formed at different times over 150,000 years ago, the most recent formation was just 15,000 years back.

UNESCO treasure. The Great Blue Hole is part of the Belize Barrier Reef Reserve System, which is protected as a World Heritage Site because it's so special and important.